Plant‐mediated effects of silica nanoparticles synthesized from rice husks on the physiology of Glyphodes pyloalis Walker (Lepidoptera: Crambidae)

Abstract

Silica nanoparticles (SiNPs) represent promising agents for enhancing plant resistance against herbivorous insects; however, the plant‐mediated effects of these nanoparticles on insect physiological processes remain insufficiently elucidated. In the present study, mulberry ( Morus spp., ‘Ken mouche’ variety) leaves were treated with SiNPs synthesized from rice husks to evaluate alterations in plant biochemical profiles. Following a 24‐h treatment period, the leaf surfaces were washed to ensure the observed effects were plant‐mediated, and the foliage was subsequently fed to Glyphodes pyloalis Walker larvae to assess potential disruptions in digestive physiology and phenoloxidase activity. SiNP application significantly elevated the concentrations of phenolics, anthocyanins and chlorophyll, as well as the activities of antioxidant enzymes and polyphenol oxidase within the mulberry leaves. Concomitantly, nutritional indices—including approximate digestibility, efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), relative consumption rate (RCR) and relative growth rate (RGR)—were significantly attenuated, while the metabolic cost increased in the larvae. Furthermore, larvae feeding on treated foliage exhibited a marked reduction in the activities of digestive serine proteases, exopeptidases, carbohydrases and lipases, alongside altered hemolymph phenoloxidase activity. These findings demonstrate that SiNPs induce host–plant biochemical defences that effectively disrupt the digestive and metabolic processes of G. pyloalis . Consequently, these results underscore the importance of plant‐mediated nanoparticle effects on insect physiology and suggest the potential of silica nanoparticles as a component in sustainable pest management strategies.